A iodine laser amplifier is known which has a gas active medium constituted by an iodized gas and means for exciting the active medium. Said means includes xenon flash tubes which can actually be disposed within the active medium. When an electric discharge is triggered in the flash tubes, ultra-violet radiation is emitted which excites the active medium. The disadvantage of such an amplifier is that it is very complex and fairly expensive, in particular when the light beam to be amplified is of large cross-section. Indeed, it then requires many flash tubes and this is expensive.
To reduce the complexity and the production cost of such amplifiers, flash tubes can be replaced by metal filaments which disintegrate at each discharge. It is then necessary to replace these filaments after each laser pulse. This is a particular disadvantage for a case where the filaments are situated in the same chamber as the medium, since the amplifier must then be emptied of gas before the filaments can be replaced.
Preferred embodiments of the present invention mitigate these drawbacks and provide a laser amplifier including means for excitation by ultra-violet radiation, which means are not very expensive and are relatively reliable.